It has previously been well known to employ counter pressure bottle filling machines for purposes of filling bottles or other containers with liquids such as beverages and the like. The structure of such filling machines, including the multiple filling heads typically employed therewith, are well known and documented such as in U.S. Pat. Nos. 3,757,835, 4,688,608 and 5,088,527, all of which are assigned to the assignee of the instant application. The invention herein relates to bottle filling machines of the nature known from these prior art references, differing primarily in the structure, implementation, and operation of a gas flow check valve attached to the end of the vent tube received within the bottle during the filling operation.
It is well known that bottle filling machines typically include a reservoir of beverage or liquid having a pressure head maintained thereabove. The bottle filling machine typically has a plurality of identical bottle filling heads circumferentially spaced about the reservoir. Each bottle filling head has a resilient seal receiving and sealing the mouth of the bottle. A counter pressure tube or vent tube extends into the bottle at one end thereof, and into the pressure head at the other. The tube has openings or orifices at each of the ends, the same being selectively sealed during the operation of the bottle filling machine.
Each of the bottle filling heads employs several valve systems controlling physical movement and/or opening and closing of the passage of the counter pressure tube. As will be appreciated from reference to prior U.S. Pat. No. 3,757,835, when a bottle is received by the resilient seal, a valve at the top of the counter pressure tube allows the pressure head above the reservoir to communicate with the interior of the bottle. The resulting pressure in the bottle opens a liquid valve assembly fixed to the bottom of the counter pressure tube. This liquid valve consists of a disc fixed to the counter pressure tube and having a tapered edge adapted to reciprocatingly engage with and separate from a fixed valve seat maintained adjacent the sealing member.
A choke valve is maintained about the counter pressure tube and is opened by the pressure of the beverage and the flow of the beverage thereacross upon opening of the liquid valve. In the prior art, when the beverage in the bottle reaches the level of an aperture or apertures in the end of the counter pressure tube, the flow of the beverage stops, for back flow of the counter pressure gas through the counter pressure tube is prevented.
Immediately upon cessation of beverage flow, the choke valve closes by spring actuation. An inner tapered surface of the choke valve sealingly engages a portion of the tapered edge of the disc of the liquid valve. A closure is obtained by overlapping engagement of the parallel tapers of the choke valve and the disc of the liquid valve. This closure immediately prevents any further flow of beverage into the bottle for release of gas from the bottle. Immediately thereafter, conventional control of a lever arm moves the counter pressure tube downwardly, causing the disc of the fluid valve to close against its seat, allowing the bottle to be depressurized, removed, capped, and cased.
A particular problem has existed with the prior art structures discussed generally above. Particularly, the gas flow passage through the vent tube in the beverage filling valve has not been given to filling accuracy, and has tended to induce foaming of carbonated beverage during the filling operation. In the prior art, the closing of the gas flow passage through the vent tube often relied simply upon the sealing of apertures at the end of the vent tube by the rising liquid. In such systems, liquid would necessarily remain in the end of the vent tube for deposit in the bottle during depressurizing or, depending on valve closure design, into the next subsequent bottle during the filling operation, the same inducing foaming in the event of carbonated beverages, a most undesirable event. Further, the simple shutting off or sealing of the vent tube apertures has been found to be inaccurate in controlling the filling height within the bottle and has not been given to repeatability from one bottle to the next.
The prior art has also taught the implementation of a ball valve to shut off the gas flow passage through the vent tube when the beverage within the bottle reaches a desired level. However, such ball valves rely solely upon buoyancy to achieve their sealing movement and liquid or beverage is often sealed above the ball within the vent tube and remains therein for deposit in the next subsequent bottle during the filling operation, again inducing foaming. Additionally, such ball valves have typically been found to fail with respect to accuracy and repeatability because closure is dependent upon the buoyancy of the ball and the velocity of the liquid passing through the exit port of the filling valve. Such gas flow check valves have also been adversely impacted by the centrifugal forces encountered in the rotating filling machines.